Recording medium, playback apparatus and recording/playback apparatus thereof

ABSTRACT

In order to search for an image recorded on an optical disk  10 , a registration trigger is generated automatically or in response to an instruction of the user from a microcomputer block  30 , a pointer indicating the recording position of a main image which is used as an index image in a preset area of the optical disk  10  via a data processor  36  and disk drive  32 , index image data which becomes the index image is created in an encoder section  50  and data is recorded from an index image buffer memory  59  into a user menu file on the optical disk  10  via a formatter  56 , data processor  36  and disk drive  32.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of Ser. No. 09/630,320,filed on Jul. 31, 2000 now U.S. Pat. No. 6,650,828, which is a divisionof Ser. No. 09/367,870, filed Sep. 3, 1999 now U.S. Pat. No. 6,263,152,which is a 371 of PCT/JP99/00220, filed Jan. 21, 1999; and claimspriority to Japanese Application No. JP 10-009906, filed Jan. 21, 1998.

TECHNICAL FIELD

This invention relates to a recording medium, playback apparatus andrecording/playback apparatus thereof and more particularly to arecordable/playable recording medium such as a DVD-RAM and arecording/playback apparatus which can be applied to arecording/playback DVD player for recording or playing back an image andvoice by use of the recording medium.

BACKGROUND ART

A playback-only optical disk having an image and voice recorded thereonis already put into practice as a music CD, laser disk, video CD or thelike. MPEG2 (Moving Picture Experts Group Phase 2) which is theinternational standard specification for compression of moving picturesand a DVD specification using the AC3 audio compression system aredefined and it is put into practice as a DVD video. The DVDspecification is initially designed by taking a playback-only disk or aROM disk which cannot be recorded by the user into consideration, butrecently, a DVD-RAM specification which can be played back and recordedby the user was made.

At present, the DVD-RAM specification is realized in a datarecording/playback apparatus for a computer, but as a matter of course,application to a DVD recording/playback apparatus for recording/playbacka moving picture and voice is studied. When application of the DVD-RAMspecification to the DVD recording/playback apparatus is considered, itis desirable to effect the searching operation in the same manner as inthe specification for DVD audio and DVD video based on the DVDspecification for playback only.

In the DVD video specification, VMG-VTS menus are provided for disktitle creating companies. The menus are created by use of an exclusiveauthoring instrument. Then, the recording content of the disk isdisplayed in the form of menu in addition to normal video data at thetime of playback and buttons are displayed by use of a sub-video imageso as to permit the user to select them, thereby making it possible tosearch for a desired portion.

On the other hand, when a moving picture is recorded by use of theDVD-RAM, the user creates a title, and if VMG•VTS menu data used in theDVD video specification is used, the user also crates them. However, itis extremely difficult for the ordinary user to create the VMG•VTS menudata when considering the large amount of data and devices which must beprepared to create the menu data and it is not practical. Further, inthe case of recordable/playable DVD, the operation for re-recording mainrecord data (video, voice data) is frequently effected, but if theVMG•VTS menu data is used, the VMG•VTS menu data must be rewritten eachtime the main record data is rewritten and the amount of operations forthis purpose becomes extremely large.

As described above, when a moving picture and voice are recorded by useof the DVD-RAM, use of VMG•VTS menu data used in the DVD videospecification in which the main record data is not assumed to berewritten imposes an extremely heavy load on the user and it is notpractical.

This invention has been made to solve the above problem and an object ofthis invention is to provided a recordable/playable recording medium andrecording/playback apparatus capable of easily effecting the searchingand editing operations without making it necessary to create troublesomemenu data.

DISCLOSURE OF INVENTION

A recording/playback apparatus according to this invention is arecording/playback apparatus for recording or playing back main recorddata containing information of at least one of an image and voice andcomprises trigger supplying means for supplying a trigger forregistering an index image; position information acquiring means foracquiring recording position information on the recording medium of animage which is now being recorded in response to a trigger supplied bythe trigger supplying means: and position recording means for recordingthe recording position information acquired by the position informationacquiring means on the recording medium at the time of termination ofthe image recording. As the recording position information, a sectornumber and cell number of an image which is now being recorded arecontained.

Further, a recording/playback apparatus according to this inventioncomprises creating means for creating index image data in response to atrigger supplied from the trigger supplying means; and index imagerecording means for recording the recording position informationacquired by the position information acquiring means and the index imagedata created by the creating means on the recording medium at the timeof termination of the image recording.

Further, a recording/playback apparatus according to this inventioncomprises time information acquiring means for acquiring display timeinformation of an image which is now being recorded in response to atrigger supplied from the trigger supplying means; and time informationrecording means for recording the display time information acquired bythe time information acquiring means on the recording medium at the timeof termination of the image recording. The recorded image is processedin the unit of program and the time information is the number of fieldscounted from the starting time of the program which is now to bedefined.

Further, a recordable/playable recording medium according to thisinvention comprises an area for recording record position information ofan image selected in the main record data; and an index image recordingarea for recording image data of the selected image in the main recorddata as an index image.

According to this invention, recording position information of an imageselected in the main record data is recorded on the recording medium andimage data of the image selected in the main record data isalternatively or additionally recorded as an index image. By usinginformation of an image and voice recorded in a recording positionindicated by the position information or the index image (compressed orreduced image data) as a menu at the time of playback, the user canimmediately detect the recording information on the recording medium.

Therefore, it becomes possible for the user to quickly search for adesired portion based on the menu or efficiently effect the editingoperation such as erase or replacement of information of a desired areaon the recording medium.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view for illustrating a recordable/playableoptical disk (DVD-RAM or DVD-RW disk) according to this invention;

FIG. 2 is a diagram for illustrating the correspondence relation betweenthe data recording area of the optical disk (DVD-RAM) of FIG. 1 and datarecording tracks recorded thereon;

FIG. 3 is a diagram for illustrating the directory structure ofinformation recorded on the optical disk of FIGS. 1 and 2;

FIG. 4 is a diagram showing the data structure of a video object setshown in FIG. 3;

FIG. 5 is a diagram showing the structure of a data pack shown in FIG.4;

FIG. 6 is a diagram showing the data structure of control informationshown in FIG. 4;

FIG. 7 is a diagram showing the contents of a playback management tableshown in FIG. 6;

FIG. 8 is a diagram showing the data structure of a PGC informationtable shown in FIG. 6;

FIG. 9 is a diagram showing the schematic contents of cell playbackinformation shown in FIG. 8;

FIGS. 10A and 10B are diagrams for illustrating the concept of PGC shownin FIG. 8;

FIG. 11 is a diagram showing the contents of PGC information managementinformation shown in FIG. 8;

FIG. 12 is a diagram showing the contents of PGC general informationshown in FIG. 8;

FIG. 13 is a diagram showing the contents of cell playback informationshown in FIG. 8;

FIG. 14 is a diagram showing the contents of PGC information managementinformation shown in FIG. 8;

FIG. 15 is a block diagram for illustrating the construction of a DVDvideo recorder used as a recording/playback apparatus according to oneembodiment of this invention;

FIG. 16 is a diagram showing one example of the registration timing ofan index image;

FIG. 17 is a flowchart showing the index image registering procedure inthe pointer recording mode in the above embodiment;

FIG. 18 is a diagram for illustrating a registering point at the time ofindex image registration in the pointer recording mode;

FIG. 19 is a flowchart showing the index image registering procedure inthe index image recording mode in the above embodiment;

FIG. 20 is a conceptual diagram showing the user menu file format in theabove embodiment;

FIG. 21 is a diagram showing the user menu file format more in detail;

FIG. 22 is a diagram showing the user menu file format more in detail;

FIG. 23 is a diagram showing one example of display of the menu screenin the above embodiment;

FIG. 24 is a diagram-showing a data format for controlling the image inthe unit of program;

FIG. 25 is a diagram showing another construction of the PGC informationmanagement table;

FIG. 26 is a diagram showing the construction of one program whichincludes a plurality of cells;

FIG. 27 is a flowchart showing the procedure for registering displaytime on the optical disk;

FIG. 28 is a diagram showing the relation between VOBU and field inMPEG;

FIG. 29 is a diagram showing the construction of a time map table; and

FIG. 30 is a flowchart showing the process for deriving a position inwhich image data is recorded from the number of fields.

BEST MODE OF CARRYING OUT THE INVENTION

There will now be described an embodiment of this invention withreference to the accompanying drawings.

As a typical embodiment of a recording/playback apparatus according tothis invention, there is provided an apparatus, for example, a DVDdigital video recorder for recording/playing back a moving pictureencoded based on MPEG2 at a variable bit rate.

FIG. 1 is a perspective view for illustrating the structure of arecordable optical disk 10 used for the DVD digital video recorder. Asshown in FIG. 1, the optical disk 10 has a structure obtained bylaminating together one pair of transparent base plates 14 each having arecording layer 17 by use of an adhesive layer 20. Each base plate 14can be formed of polycarbonate with a thickness of 0.6 mm and theadhesion layer 20 can be formed of extremely thin ultraviolet curingresin (for example, 40 μm thick). By laminating the pair of 0.6 mm baseplates together with the recording layers 17 disposed on the respectivesurfaces of the adhesive layer 20, the optical disk 10 of large capacitywith a 1.2 mm thickness can be obtained.

A central hole 22 is formed in the optical disk 10 and a clamp area 24for clamping the optical disk 10 at the rotational driving time isprovided around the central hole 22 on each surface of the disk. Thespindle of a disk motor is inserted into the central hole 22 when theoptical disk 10 is loaded on a disk drive device (not shown). Theoptical disk 10 is clamped in the clamp area 24 during the rotation bymeans of a disk clamper (not shown).

The optical disk 10 has an information area 25 in which video data,audio data and other information can be recorded around the clamp area24. A lead-out area 26 is provided on the outer peripheral side of theinformation area 25 and a lead-in area 27 is provided on the innerperipheral side thereof in contact with the clamp area 24. A datarecording area 28 is defined between the lead-out area 26 and thelead-in area 27.

A recording track is continuously formed in a spiral form, for example,on the recording layer 17 of the information area 25. The continuousrecording track is divided into a plurality of physical sectors andconsecutive numbers are attached to the sectors. The sector is used as arecording unit to record various data on the optical disk 10.

The data recording area 28 is an actual data recording area and, forexample, video data (main video data) of a movie or the like, sub-videodata such as caption, menu or the like, and audio data such as speechesand sound effects are recorded in the form of phase change marks asrecording/playback information.

The optical disk 10 is a recording/playback RAM disk and the recordinglayer 17 is formed of a three-layered structure having a phase changerecording material layer formed of a Ge₂Sb₂Te₅ layer held between twolayers of zinc sulfide/silicon oxide mixture (ZnS/SiO₂), for example. Acontinuous groove is formed in the base plate 14 having therecording/playback recording layer 17 and the phase change recordinglayer is formed on the groove. Generally, the phase change recordinglayer on the land portion other than the groove is also used forinformation recording.

A DVD digital video recorder which will be described later isconstructed to effect the repetitive recording operation, repetitiveplayback operation (read/write operation) for a DVD-RAM disk (or DVD-RWdisk) and the repetitive playback operation for a DVD-ROM disk.

FIG. 2 is a diagram for illustrating the correspondence relation betweenthe data recording area 28 of the optical disk (DVD-RAM) 10 of FIG. 1and the recording track of data recorded thereon. If the disk 10 is aDVD-RAM, the main body of the disk 10 is inserted into a cartridge 11 toprotect the delicate disk surface. When the DVD-RAM disk 10 is insertedtogether with the cartridge 11 into the disk drive of the DVD videorecorder which will be described later, the disk 10 is extracted fromthe cartridge 11, clamped on the turn table of a spindle motor (notshown) and rotated and driven while it is set to face an optical head(not shown).

The data recording track is continuously formed in a spiral form on therecording layer 17 of the information area 25 shown in FIG. 1. As shownin FIG. 2, the continuous track is divided into a plurality of logicalsectors (minimum recording unit) of constant recording capacity and datais recorded by using the logical sector as a reference. The recordingcapacity of one logical sector is set to 2048 bytes (or 2 kbytes) whichis the same as one pack data length as will be described later.

The data recording area 28 is an actual data recording area andmanagement data, main video data, sub-video data and voice (audio) dataare similarly recorded.

FIG. 3 shows the hierarchical structure of data recorded on the opticaldisk 10 used as an information recording medium on which videoinformation and music information shown in FIGS. 1 and 2 can be recordedand played back. The data recording area 28 formed on the optical disk10 has a data hierarchical structure as shown in FIG. 3. For example,the logical format of the structure is defined in conformity to theuniversal disk format (UDF) bridge and IS09660 which is a standardspecification.

As shown in FIG. 3, the lead-in area 27 is formed on the innerperipheral side of the optical disk 10, the lead-out area 26 is formedon the outer peripheral side thereof, the data recording area 28 betweenthe lead-in area 27 and the lead-out area 26 is assigned as a volumespace 28, and the volume space 28 includes a space (volume/filemanagement area 70) for information of the volume and file structure anda space (DVD data area 72) for application of the DVD specification.

The lead-in area 27 includes a read-only emboss zone having an opticalreflection surface formed in an irregular form, a mirror zone having aflat mirror surface and a rewritable data zone in which information canbe rewritten. The lead-out area 26 includes a rewritable data zone inwhich information can be rewritten.

Information associated with the entire portion of the informationrecording medium such as a physical sector number indicating therecording start/recording end position, recording density, disk size,disk type of the DVD-ROM (read-only DVD disk), DVD-RAM (DVD disk forrecording/playback) and DVD-R (additionally recording type DVD disk) isrecorded on the emboss data zone of the leak-in area 27, for example,and information associated with the recording/playback/erasecharacteristics such as the recording power and recording pulse widthrequired for recording data on the recording layer 17, erase powerrequired for erasing data recorded on the recording layer 17, playbackpower required for playing back data recorded on the recording layer 17,and linear velocity at the time of recording/erase is also recorded.Further, information associated with the manufacturing of eachinformation recording medium such as a manufacturer's serial number isrecorded on the emboss data zone of the leak-in area 27. In therewritable data zone of the lead-in area 27 and the rewritable data zoneof the lead-out area 26, a recording area for recording an inherent diskname of each information recording medium, a trial recording area fordetermining whether or not the recording and erase operations can beeffected in the recording/erase condition, and a management informationrecording area for determining whether or not a defective area ispresent in the data area 72 and recording an address of the area areprovided and a preparation process for permitting data to be recorded onthe data area 72 is effected in the above area and information necessaryfor data recording/erase/playback after this is recorded in the area.

The volume space 28 is physically divided into a large number of sectorsand consecutive numbers are attached to the physical sectors. Thelogical address of data recorded in the volume space (data recordingarea) 28 indicates a logical sector number as defined by the IS09660 andUDF bridge. Like the effective data size of the physical sector, thelogical sector size is set to 2048 bytes (2 kbytes) and consecutivenumbers are attached according to the ascending order of the physicalsector numbers as the logical sector numbers.

The volume space 28 has a hierarchical structure and includes avolume/file management area 70 and a data area 72 formed of at least onevideo object. The areas 70, 72 are divided on the boundary between thelogical sectors. One logical sector is defined to have 2048 bytes andone logical block is also defined to have 2048 bytes. Therefore, onelogical sector is defined to be the same as one logical block.

The volume/file management area 70 is a rewritable data zone in whichdata can be rewritten by the user and corresponds to a management areadefined by the IS09660 and UDF bridge and information associated withthe whole volume or a file of audio/video data is stored in a systemmemory (not shown) in the DVD video recorder as will be described laterbased on the description of the area 70. Generally, the volume/filemanagement area 70 is constructed by one file.

As shown in FIG. 3, in the data area 72, an area in which computer dataand audio/video data can be recorded together is defined. The recordingorder of the computer data and audio/video data and the recordinginformation size can be arbitrarily set, areas in which the computerdata is recorded are referred to as computer data areas 74-1, 74-2, andan area in which audio/video data is recorded is referred to as anaudio/video data area 76.

The computer data areas 74-1, 74-2 are not particularly necessarilyprovided from the viewpoint of its property if only audio/video data isrecorded in the recording area 72 and the audio/video data area 76 isnot particularly necessarily provided from the viewpoint of its propertyif only computer data is recorded in the recording area 72. The computerdata areas 74-1, 74-2 and the audio/video data area 76 can be formed ofone file or a plurality of files.

As shown in FIG. 3, in the audio/video data area 76, control information78 necessary when the processes such as image recording (soundrecording), playback, edition and searching operations are effected anda video object set 80 formed of one or a plurality of objects 82, 84, 86as the reproduction object or the contents thereof are recorded. In thevideo object set 80, the video object 82 whose contents are video data,the picture object 84 whose contents are a still picture such as astill/slide picture or picture data such as a searching or editing indeximage or a location of a desired portion of video data, and the audioobject 86 whose contents are audio data are provided. As is clearlyunderstood, the video object set 80 is not required to have all of theobjects 82, 84, 86 and may be constructed by at least one of the objects82, 84, 86. Likewise, the objects 82, 84, 86 are each constructed by oneor a plurality of files.

As shown in FIG. 4, in the video object set 80 constructed by one or aplurality of objects 82, 84, 86, video data (video pack 88 which will bedescribed later) compressed according to the MPEG2 specification, audiodata (audio pack 90 which will be described later) compressed accordingto the preset specification or non-compressed and sub-video data(sub-video pack 92 including bit map data in which one pixel isconstructed by a plurality of bits as will be described later)compressed according to the run-length are stored.

If the video object set 80 is constructed only by the video object 82,it has a data structure as shown in FIG. 4, if the video object set 80is constructed only by the picture object 84, it has a data structureconstructed only by the sub-video pack 92 and/or the video pack 88 whichdoes not include the audio pack 90, and if the video object set 80 isconstructed only by the video object 86, it has a data structureconstructed only by the audio pack 90 which does not include thesub-video pack 92 and video pack 88.

As shown in FIG. 4, logically, the video object set 80, that is, thevideo, picture and audio objects 82, 84, 86 are constructed by aplurality of cells 94 and each cell 94 is constructed by at least onevideo object unit (VOBU) 96.

In the cell 94, the video object unit (VOBU) 96 is decoded and playedback in the arrangement order in the cell 94 as a rule. The video objectunit 96 is a set (pack string) of the video pack (V pack) 88, audio pack(A pack) 90 and sub-video pack (SP pack) 92 and defined as data playedback in a preset period, for example, in a period of 0.5 to 1.2 seconds.Each pack is a minimum unit used for effecting the data transfer processand the cell is logically the minimum unit used for effecting the dataprocess.

Identification numbers (IDN#k; k=0 to k) are attached to the videoobject units (VOBU) 96 and the video object unit 96 can be specified bythe identification number. The playback period of the video object unit(VOBU) 96 normally corresponds to a playback period of video dataconstructed by at least one video group (group of pictures; GOP)contained in the video object unit 96. Generally, the length of one GOPis approx. 0.5 second in terms of the MPEG2 specification and image datacompressed to play back the frame images of approx. 15 sheets during theabove period is stored.

If the video object unit (VOBU) 96 includes video data, GOPs (inconformity to the MPEG specification) including the video pack 88,sub-video pack 90 and audio pack 92 are arranged to construct a videodata stream. If playback data is formed of only the audio and/orsub-video data, the playback data is constructed with the video objectunit (VOBU) 96 used as one unit. For example, the audio pack 90 to beplayed back in a playback period of the video object unit (VOBU) 96 towhich target audio data belongs is stored in the video object unit(VOBU) 96.

Identification numbers (IDN#i=0 to i) are attached to the video objects82, 84, 86 constructing the video object set 80 and the video objects82, 84, 86 can be specified according to the identification number.Further, identification numbers (C_IDN#j) are attached to the cells 94like the case of the video objects 82, 84, 86.

FIG. 5 shows the general structure of the video pack 88, sub-video pack92 and audio pack 90. Like the logical sector of FIG. 2, the packs areeach constructed by data of 2048 byte unit. As shown in FIG. 5, thevideo, audio and sub-video packs 88, 90, 92 are each constructed by apack header 98 and a packet 100. The packet 100 includes a packet headerin which a decode time stamp (DTS) and presentation time stamp (PTS) arerecorded.

The control information 78 shown in FIG. 3 includes playback controlinformation 102 indicating control information necessary at the time ofplayback, recording control information 104 indicating controlinformation necessary at the time of recording (image recording or soundrecording), edition control information 106 indicating controlinformation necessary at the time of edition and index image controlinformation 108 indicating management information associated with asearching or editing index image of a desired position of video data.

As shown in FIG. 6, the playback control information 102 shown in FIG. 3includes a management information table (PLY_MAT) 112, program chain(PGC) information table (PGCIT) 110 and time map table 111. Informationas shown in FIG. 7 is described in the management information table(PLY_MAT) 112 and the program chain (PGC) information table 110 has adata structure as shown in FIG. 8.

In the program chain (PGC) information table 110, information associatedwith the playback order of cells and the program chain (PGC) is mainlydescribed and data of the cell 94 recorded in the video object 82 (thatis, movie data used as real data constructed by the video object unit96) is played back according to the description of the program chain(PGC) information table 110. As shown in FIG. 8, the program chain (PGC)information table 110 is constructed by index scene information 120, PGCinformation management information 122, search pointers #1 to #n 124 forsearching each PGC information and PGC information #1 to #n 126. In theindex scene information 120, cell numbers of scenes (index scenes) usedas index images are described.

If the PGC number is determined, PGC information corresponding to thePGC number is obtained by referring to the search pointer 124. Theplayback order of cells is derived from the PGC information, data of thecells 94 as real data is acquired from the video object 82 according tothe playback order of cells and video data is played back. In this case,the video object 82 is explained, but cell data is derived as real dataand played back according to the description of the program chain (PGC)information table 110 in the same manner as in the case of the pictureobject 84 and audio object 86.

In this case, the PGC corresponds to the chapter of the movie story andindicates a unit in which a series of playback operations for specifyingthe playback order of cells is effected. In other words, if one PGCcorresponds to one drama, it is possible to consider that a plurality ofcells 94 constructing the PGC correspond to various scenes in the drama.The contents of the PGC (or the contents of the cells) may be determinedby a software provider making the contents recorded on the disk 10, forexample. More specifically, if a video data stream as shown in FIG. 10Ais present, the contents thereof are divided into video object units 96which are played back in a preset period of time and a set of videoobject units 96 which are continuous in principle are defined in thecell 94.

Since the video object unit 96 is continuous in principle, the cell 94is defined by the first video object unit 96 and the last video objectunit 96 constructing the cell 94 in the PGC information table 110 aswill be described later, more specifically, in the cell playbackinformation 130 shown in FIG. 8. That is, information in a playbacksegment specified by a start address 134 and end address 136 of playbackdata constructing the cell as shown in FIG. 9 is described in the cellplayback information 130.

If the cell 94 is thus defined, the PGC is constructed by determiningthe playback order of the cell. For example, as shown in FIG. 10B, thePGC #1 is defined by arranging the three cells 94 in the cell playbackinformation table so as to play back the cells in the order of cell-A,cell-B, cell-C. Likewise, the PGC #2 is defined by arranging the threecells 94 in the cell playback information table so as to play back thecells in the order of cell-D, cell-E, cell-F. Further, the PGC #3 isdefined by arranging the five cells 94 in the cell playback informationtable so as to play back the cells in the order of cell-Q, cell-R,cell-S, cell-T, cell-U.

The PGC #2 corresponding to a chapter which continues from the PGC #1corresponding to a previous chapter is played back by linking the PGC #1and PGC #2 together. In other words, the cells are successively playedback in the order of cell-A to cell-F. In the PGC, the cells 94 areplayed back in the arrangement order thereof, but the construction ofthe PGC and the playback order of the PGC are arbitrarily set.Therefore, for example, a PGC can be defined by use of the cellsconstructing another PGC. Further, since the way of linking or linkinformation can be arbitrarily determined, various stories can be formedor edited. For example, it is possible to link the PGC #3 following thePGC #1 or add the same cell, for example, the cell G, to the PGC #1-andPGC #2 to make different chapters. That is, a desired story can berealized by linking the PGC #3 to the PGC #1 or PGC #2 according to theselection by the user.

In the playback management table 112 shown in FIG. 7, an identifier IDindicating playback control information is described, a start address(VOBS_SA) and end address (VOBS_EA) of the video object set 80 aredescribed and an end address (CTLI_EA) of control information (CTLI) 78and an end address (PLYI₁₃EA) of playback control information (PLYI) 102are described. Further, in the playback management table 112, attribute(CAT) indicating that the management information attributes to theformat of the recording/playback DVD is described to indicate attributeof video data in the video object set recorded in the audio/video dataarea 76, for example, the attribute of NTSC system or wide-televisionsystem. Further, in the playback management table 112, the number(AST_Ns) of audio streams in the video object set and a table (AST_ATR)in which the attribute thereof, for example, the compression system orthe like is described are described and the number (SPST_Ns) ofsub-video streams in the video object set and a table (SPST_ATR) inwhich the attribute thereof is described are described. If the userrecords searching index image data and menu image data as an independentuser menu file in the audio video data area 76,-a flag (01) indicatingthat the user menu is present or a flag (00) indicating no user menu ifthe menu is not present is described. If the index image is recorded inthe audio video data area 76, the number of a PGC which is used as thebasis of a typical index image is described. Further, a flag (0: not yetplayed back, 1: already played back) indicating whether the playbackoperation by the user for the video object set controlled by the controlinformation 78 is terminated or not is described.

As shown in FIG. 11, in PGC information management information (PGC_MAI)122 shown in FIG. 8, information indicating the total number of PGCs iscontained and information pointing the head portion of each PGCinformation is contained as described before in the search pointer 124of PGC information to make it easy to search for the PGC. PGCinformation 126 is constructed by PGC general information 128 shown inFIG. 8 and at least one cell playback information 130 shown in FIG. 8.

As shown in FIG. 11, in the PGC information management information(PGC_MAI) 122, the end address (PGC_TABLE_EA) of the PGC informationtable 110, the end address (PGC_MAI_EA) of the PGC informationmanagement information (PGC_MAI) 122, the start address (PGC_SRP_SA) andend address (PGC_SRP_EA) of the PGC information search pointer (PGC_SRP)124, the start address (PGCI_SA) and end-address (PGCI_EA) of all of thePGC information items (PGCI) 126 and the number (PGC_Ns) of all of thePGCs are described.

As shown in FIG. 12, in the PGC general information (PGC_GI) 128,information indicating the number of cells and the playback time of thePGC is described. That is, in the PGC general information (PGC_GI) 128,the contents (PGC_CNT) of the PGC in which the number of cells and thenumber of PGCs are described, the playback time (PGC_PB_TM) of the PGC,a table (PGC_AST_CTL) in which information for controlling the audiostream contained in the PGC is described, and a table (PGC_SPST_CTL) inwhich information for controlling the sub-video stream contained in thePGC is described are described.

Further, in the PGC general information (PGC_GI) 128, PGC navigationcontrol (PGC_NV_CTL) in which link information associated with the PGCto be linked with the PGC, for example, a preceding PGC, next PGC or askipped (GOup) PGC is described, a sub-video pallet table (PGC_SP_PLT)in which reproduction information associated with color of sub-videopallet is described and the start address (PGC_PGMAP_SA) of a programtable (not shown) in which a list of programs constructing the PGC isdescribed are described. Further, in the table (PGC_GI), the startaddress (CELL_PLY_I_SA) of cell playback information (CELL_PLY_I) 120, aflag (01: menu data is present, 00:-menu data is not present) indicatingwhether menu data associated with the PGC and formed by the user ispresent or not, reservation, a flag (0: not yet played back, 0: alreadyplayed back) indicating whether the playback operation for the PGC bythe user is completed or not and a flag (ARCHIVE Flag) indicatingwhether or not it is desired to hold the PGC after this, that is, a flag(0: free [erasable], 1: permanent storage) indicating whether or not itis desired to permanently store the PGC are described.

In the index scene information 120 shown in FIG. 8, the cell number N ofa scene registered as an index image in the pointer recording mode whichwill be described later is described.

As shown in FIG. 9, the cell playback information (CELL_PLY_I) 130 shownin FIG. 8 is roughly divided into cell general information 132 and indexscene pointer information 134.

As shown in FIG. 13, in the cell general information 132, the category(C_CAT) of a cell, for example, information indicating whether or notthe cell belongs to a block and whether or not the block is an angleblock if it belongs to the block is described. In this case, the angleblock indicates a block whose angle can be switched. The angle switchingindicates that an angle (camera angle) at which an object image isviewed is changed. More specifically, in a musical performance scene (inthe-same event) of the same music in a rock concert video, for example,it indicates that various scenes such as a scene obtained by viewing thevocalist as a main object, a scene obtained by viewing the guitarist asa main object and a scene obtained by viewing the drummer as a mainobject can be observed at different angles. As the case wherein theangle switching (or angle changing) is made, a case wherein the anglecan be selected according to the preference of the audience or a casewherein the same scene is automatically repeated in the development ofthe story while changing the angle (a case wherein the softwarecreator/provider makes the story to attain the above effect or a casewherein the user of the DVD video recorder edits the story to attain theabove effect) is provided.

Further, as shown in FIG. 13, in the cell general information 132, cellplayback time (absolute time) in the PGC is described and a flag (0: notyet played back, 1: already played back) indicating whether or not theplayback operation of the cell by the user is terminated and a flag(ARCHIVE Flag) indicating whether or not it is desired to hold the cellafter this, that is, a flag (0: free [erasable], 1: permanent storage)indicating whether or not it is desired to permanently store the cellare described.

Further, as shown in FIG. 13, in the cell general information 132, acell start address (CELL_SA) and end address (CELL_EA) are described.The cell start address and end address are described by use of relativeaddresses of the first and last video object units (VOBU) of the cellfrom the head of the video object set 80. Further, in the cell generalinformation 132, the end address (CELL_PLY_I_EA) of the cell playbackinformation (CELL_PLY_I) 130 is also described. The end address of thecell playback information is provided since the length of the indexscene pointer information 134 is not constant although the length of thecell general information is constant.

As shown in FIG. 13, in the index scene pointer information 134, aphysical sector number (which is referred to as an index scene pointeraddress (INDEX_PT)) of PGC information containing the cell number of anindex scene (which is a scene used as an index image) recorded in theindex scene information 120 is described. In FIG. 13, M index scenepointer addresses are provided and M is a variable number.

Therefore, at the time of searching for an image recorded on the opticaldisk 10, an index image can be searched for by reading the cell numberof a cell containing the index scene from the index scene information120 in the PGC information table 110 shown in FIG. 8 and searching thePGC information 126 containing the cell number to read the index scenepointer information 134 on the cell playback information 130 in the PGCgeneral information 128 of the PGC information 126.

The procedure for registering the cell number into the index sceneinformation 120 and registering the index scene pointer information 134is described later in detail.

The recording control information 104 shown in FIGS. 3 and 6 contains arecording management table 114 shown in FIG. 14 and the end address(RECI_EA) of the recording control information 104 and the end address(REC_MAT_EA) of the recording management table 114 are described in therecording management table 114 and a free area (FREE_SPACE) for writinginformation associated with the recording management is provided.Further, in the recording management table 114, a flag (ARCHIVE Flag)indicating whether or not it is desired to hold the VOBU or a flag (0:free [erasable], 1 permanent storage) indicating whether or not it isdesired to permanently hold the VOBU is described.

The reduced drawing control information 108 shown in FIG. 3 includes afirst anchor pointer 108-A, picture address table 108-B and a secondanchor pointer 108-C, and the picture address table 108-B includes menuindex information INFO1, index picture information INFO2, informationpicture information INFO3, defective area information INFO4 and wallpaper picture information INFO5.

FIG. 15 shows the construction of a device (DVD video recorder) used forrecording/playing back digital moving image information at a variablerecording rate with respect to the disk of FIG. 1 by use of informationwith the construction explained with reference to FIGS. 3 to 14.

The device main body of the DVD video recorder rotates and drives theoptical disk 10 which is a DVD-RAM or DVD-R disk, for example, and isconstructed by a disk drive section (disk drive 32, temporary storagesection 34, data processor 36, system time counter 38 and the like) forreading/writing information with respect to the optical disk 10, anencoder section 50 constructing the recording section, a decoder section60 constructing the playback section, and a microcomputer block 30 forcontrolling the operation of the device main body.

The encoder section 50 includes an ADC (analog-digital converter) 52,video encoder (V encoder) 53, audio encoder (A encoder) 54, sub-videoencoder (SP encoder) 55, formatter 56, buffer 57, index image creatingsection 58 and index image buffer memory 59.

The ADC 52 is supplied with an external analog video signal and externalanalog audio signal from the AV input section 42, or an analog TV signaland analog voice signal from the TV tuner 44. The ADC 52 converts aninput analog video signal into a digital form with a sampling frequency13.5 MHz and quantization bit number of 8 bits, for example. That is, aluminance component Y, color difference component Cr (or Y—R) and colordifference component Cb (or Y—B) are quantized by use of 8 bits.Further, the ADC 52 converts an input analog audio signal into a digitalform with a sampling frequency 48 kHz and quantization bit number of 16bits, for example.

When an analog video signal and digital audio signal are input to theADC 52, the ADC 52 passes the digital audio signal therethrough as itis. At this time, a process for reducing the jitter attached to thedigital signal or a process for changing the sampling rate orquantization bit number may be effected without changing the contents ofthe digital audio signal. Further, when a digital video signal anddigital audio signal are input to the ADC 52, the ADC 52 passes thedigital video signal and digital audio signal therethrough as they are.The jitter reducing process or sampling rate changing process may beeffected without changing the contents of the digital signals.

The digital video signal component from the ADC 52 is supplied to theformatter 56 via the video encoder (V encoder) 53. The digital audiosignal component from the ADC 52 is supplied to the formatter 56 via theaudio encoder (A encoder) 54.

The V encoder 53 has a function of converting the input digital videosignal into a compressed digital signal at a variable bit rate based onthe MPEG2 or MPEG1 specification.

The A encoder 54 has a function of converting the input digital audiosignal into a digital signal (or digital signal of linear PCM)compressed at a fixed bit rate based on the MPEG audio or AC-3specification.

When a DVD video signal with data construction shown in FIGS. 4 and 5 ora signal from the DVD video player with independent output terminal forthe sub-video signal is input from the AV input section 42 or when theDVD video signal with the above data construction is broadcasted andreceived by the TV tuner 44, the sub-video signal component (sub-videopack) in the DVD video signal is input to the sub-video encoder (SPencoder) 55. The sub-video data input to the SP encoder 55 is convertedinto a preset signal configuration and then supplied to the formatter56.

The formatter 56 performs the preset signal processing for the inputvideo signal, audio signal, sub-video signal and the like while usingthe buffer memory 57 as a work area and outputs record data whichcoincides with the above format (file structure) to the data processor36.

Now, the standard encode processing contents for creating the aboverecord data is simply explained. If the encode process is started in theencoder section 50 of FIG. 15, parameters necessary for encoding video(main video) data and audio data are set. Next, the main video data ispre-encoded by use of the set parameters and a distribution code amountsuitable for the set average transfer rate (recording rate) is derived.The main video data is encoded based on the distribution code amountobtained by the pre-encoding operation. At this time, the encodingoperation for the audio data is simultaneously effected.

In a case where the data compression amount is insufficient, forexample, in a case where a desired program cannot be stored into theDVD-RAM disk or DVD-R disk to be used for recording as the result ofpre-encoding, the partial encoding operation for the main video data iseffected again and the main video data which is encoded again issubstituted for a main video data portion previously pre-encoded if achance for pre-encoding the main video data again can be obtained, thatis, if the recording source is a repetitive playable source such as avideo tape or video disk, for example. The main video data and audiodata are encoded by a sequence of processes and the value of an averagebit rate necessary for recording is significantly reduced. Likewise, aparameter necessary for encoding the sub-video data is set and theencoded sub-video data is formed.

The main video data, audio data and sub-video data thus encoded arecombined and converted into a structure of video object.

That is, a cell used as a minimum unit of the main video data (videodata) is set and playback information (C_PLY_I) as shown in FIG. 13 iscreated. Next, the construction of the cell constructing the programchain (PGC) and the main video, sub-video and audio attributes are set(as part of the attributes, information obtained when corresponding datais encoded is used) and the playback control information 102 includingvarious information items explained with reference to FIGS. 3 and 6 iscreated.

The encoded main video data, audio data and sub-video data are finelydivided into packs with a preset size (2048 bits) as shown in FIG. 5. Inthe packs, time stamps such as a PTS (presentation time stamp) and DTS(decode time stamp) are adequately described. As the PTS of thesub-video, time delayed by a given amount with respect to the PTS of themain video data or audio data of the same playback time range can bedescribed.

The pakcs are set into the VOBU 96 as data played back in a presetperiod of time so as to be played back in the time stamp order of thepacks and each data cell is defined while arranging the VOBUs 96 and aVOB 82 constructed by a plurality of cells is formed. The VOBS 80obtained by combining at least one VOB is formatted into a structureshown in FIG. 4.

The disk drive section for effecting the information reading/writing(image recording and/or playback) with respect to the DVD disk 10includes a disk changer section (not shown), disk drive 32, temporarystorage section 34, data processor 36, and system time counter (orsystem time clock; STC) 38.

The temporary storage section 34 buffers a preset amount of data amongdata (data output from the encoder section 50) written into the disk 10via the disk drive 32 or buffers a preset amount of data among data(data input to the decoder section 60) played back from the disk 10 viathe disk drive 32.

For example, if the temporary storage section 34 is constructed by a4-Mbyte semiconductor memory (DRAM), the buffering of playback data orrecord data of approx. 8 seconds at the average recording rate of 4 Mbpscan be attained. Further, if the temporary storage section 34 isconstructed by a 16-Mbyte EEPROM (flash memory), the buffering ofplayback data or record data of approx. 30 seconds at the averagerecording rate of 4 Mbps can be attained. Also, if the temporary storagesection 34 is constructed by a 100-Mbyte micro HDD (hard disk), thebuffering of playback data or record data of more than 3 minutes at theaverage recording rate of 4 Mbps can be attained.

The temporary storage section 34 can be used to temporarily storerecording information until the disk 10 is replaced by a new disk whenthe disk 10 is used up in the course of recording. Further, when ahigh-speed drive (higher than twice the original speed) is used as thedisk drive 32, the temporary storage section 34 can be used totemporarily store data which is excessively read out in comparison withthe case of normal drive in a preset period of time. If readout data atthe time of playback is buffered in the temporary storage section 34, aplayback image can be prevented from being interrupted by substitutingplayback data buffered in the temporary storage section 34 even when anoptical pickup (not shown) causes a readout error due to vibration shockor the like.

The data processor 36 of FIG. 15 supplies DVD record data from theencoder section 50 to the disk drive 32, extracts a DVD playback signalplayed back from the disk 10 from the drive 32, rewrites managementinformation recorded on the disk 10, or deletes data (file or VTS)recorded on the disk 10 according to the control of the microcomputerblock 30.

The microcomputer block 30 includes an MPU (or CPU), a ROM in whichcontrol programs are stored and a RAM which provides a work areanecessary for execution of the program.

The contents to be notified to the user of the DVD video recorder amongthe results of execution by the MPU 30 are displayed on the displaysection 48 of the DVD video recorder or displayed on a monitor displayin an on-screen display (OSD) manner.

The timings at which the MPU 30 controls the disk changer section, diskdrive 32, data processor 36, encoder section 50 and/or decoder section60 can be set based on time data from the STC 38. The recording/playbackoperation is normally effected in synchronism with the time clock fromthe STC 38 and the other process may be effected at a timing independentfrom the STC 38.

The data section 60 includes a separator 62 for separating andextracting each pack from the DVD playback data having the packconstruction as shown in FIG. 5, a memory 63 used at the time of packseparation or execution of the other signal processing, a video decoder(V decoder) 64 for decoding main video data separated by the separator62, a sub-video decoder (SP decoder) 65 for decoding sub-video data(sub-video pack 90) separated by the separator 62, an audio decoder (Adecoder) 68 for decoding audio data (audio pack 91 of FIG. 9) separatedby the separator 62, a video processor 66 for adequately combining thesub-video data from the SP decoder 65 with the video data from the Vdecoder 64, superposing the menu, highlight button, caption and othersub-video image on the main video image and outputting the result ofsuperposition, a video digital/analog converter (V•DAC) 67 forconverting a digital video output from the video processor 66 to ananalog video signal, and an audio digital/analog converter (A•DAC) 67for converting a digital audio output from the audio processor 68 to ananalog audio signal.

The analog video signal from the V•DAC 67 and the analog audio signalfrom the A•DAC 67 are supplied to external components (not shown)(2-channel to 6-channel multi-channel stereo device+ monitor TV orprojector) via an AV output section 46.

Next, the basic data processing operations, that is, the recordingprocess and playback process of the DVD video recorder according to thisembodiment are explained.

At the time of data processing for recording, if the user first effectsthe key-in operation and the MPU of the microcomputer block 30 receivesa recording instruction, necessary management data is read out from theDVD disk 10 via the disk drive 32 to determine an area in which videodata is recorded. Then, the thus determined area is set in themanagement area and the recording start address of video data is set onthe disk drive 32.

In this case, the management area specifies the file management section70 (specifies the directory decode in IS09660) for managing the filesand control information 78 and parameters necessary for the filemanagement section are sequentially recorded.

Next, the microcomputer block 30 resets time of the STC section 38. Inthis example, the STC 38 is a timer of the system and therecording/playback operation is effected with the time thereof used as areference. After this, the microcomputer block 30 sets the contents ofother sections.

The flow of a video signal is as follows. That is, an AV signal inputfrom the TV tuner section 44 or external input section is A/D convertedby the ADC 52 and the video signal and audio signal are respectivelysupplied to the video encoder 53 and audio encoder 54, and the closedcaption signal from the TV tuner 44 or the text signal of textbroadcasting is supplied to the SP encoder 55.

The encoders 53, 54, 55 compress the respective input signals to makepackets (in this case, each packet is made such that each pack has 2048bytes when each packet is formed into packs) and the packets are inputto the formatter section 56. In this case, the encoders 53, 54, 55determine and record PTS, DTS of each packet according to the value ofthe STC 38 as required.

The formatter 56 temporarily holds packet data to the buffer memory 57,and then sets each input packet data into packs, mixes the packs foreach GOP and supplies the result of mixing to the data processor 36.

The data processor 36 deals with every 16 packs as an ECC (errorcorrection code) block and supplies the same to the disk drive 32 afterattaching the ECC thereto. However, if the disk drive 32 does not makeready for recording on the disk 10, data is transferred to the temporarystorage section 34, the standby state is kept until the preparation forrecording data is set up, and data recording is started when thepreparation is set up. In this case, it is assumed that the temporarystorage section 34 is formed of a large-capacity memory since it holdsrecord data of several minutes or more by high-speed access.

At the time of termination of the recording operation, informationnecessary for the volume & file management area 70 and the playbackcontrol information 102 of the control information are recorded and therecording operation is terminated. In this case, the microcomputer block30 can effect the read/write operation with respect to the dataprocessor 36 via a microcomputer bus to read/write the volume & filemanagement area 70 of the file.

In the data processing at the time of playback operation, the user firsteffects the key-in operation and the microcomputer block 30 receives aplayback instruction and the volume & file management area 70 is readout via the data processor 36 by use of the disk drive 32 to determinethe address to be played back. In this case, the volume & filemanagement area 70 indicates the volume descriptor and file managementsection. That is, whether the optical disk 10 is a DVD disk or not isdetermined by use of the volume descriptor and the control information78 is read out by use of address information of the file managementsection to determine the playback start address in the video object 82,84 or 86 corresponding to the title played back by the controlinformation 78.

Next, the microcomputer block 30 supplies a read instruction and addressof previously determined data to be played back to the disk drive 32.The disk drive 32 reads out sector data from the disk 10 according tothe supplied instruction, corrects the error in the data processor 36,and outputs the data in a pack data form to the decoder section 60.

In the decoder section 60, the separator 62 receives the readout packdata, forms the data into a packet form, transfers the video packet data(MPEG video data) to the video decoder 64, transfers the audio packetdata to the audio decoder 68, and transfers the sub-video packet data tothe SP decoder 65.

After this, the decoders 64, 65, 68 effect the playback processes insynchronism with the values of the PTS (presentation time stamp) of therespective packet data items (output packet data decoded at the timingat which the values of the PTS and STC 38 coincide with each other) andcan supply a moving picture with voice caption to the TV.

Next, the feature of this invention of the registration procedure ofindex scene to the optical disk 10 is explained by taking a case whereinan index image is most frequently used as the index scene as an example.

The index image is an image used for searching or editing the recordingcontents of the optical disk 10. As the method for registering the indeximage in this embodiment, two methods are provided which include amethod (which is called a pointer recording mode) for recording positioninformation (pointer) indicating the recording position of the indeximage in the main record data (video data) on the optical disk 10 and amethod (which is called an index image recording mode) for recordingindex image data created from the input video data by the index imagecreating section 58 on the optical disk 10.

According to the pointer recording mode, the index image can beexpressed by use of a pointer to the main image without particularly andactually creating an index image. Therefore, since the index image isnot actually provided, an advantage that the disk capacity used isreduced accordingly can be attained. However, since the index image isdisplayed while it is created on the decoder side at the time of menudisplay, the disk searching operation is frequently effected and ittakes a bit long time to display the user menu in comparison with theindex image recording mode.

For registration of the index image, the above two modes may beselectively used by the specification of the user or both of therecording modes may be combined. in this embodiment, a case wherein bothrecording modes are combined is explained.

For registration of the index image, the device automatically detectsthe recording start/termination, for example, as shown in FIG. 16,images 1, 2 of a cell-1 can be registered at the recording start time ofthe cell-1 or an image 5 of the last frame of a cell-3 can be registeredat the recording termination time. Further, the user can register theimage by manually effecting the key-in operation or the like while theuser monitors the image which is now being recorded on the displayscreen. In this case, as shown by images 3, 4 in FIG. 16, a plurality ofdesired images in the cell-2 generated during the recording operationcan be registered.

First, the index image registration procedure in the pointer recordingmode is explained by use of the flowchart shown in FIG. 17.

If the user issues a registration instruction of the index image via akey-in section 49, the MPU in the microcomputer block 30 determines thatthe registration trigger is present as shown in the step S101, issues aregistration trigger to the encoder section 50, receives a GOP creationstart signal from the video encoder 53, and detects the start of the Ipicture creation operation which will be described later (step S102).The I picture is used as an index image and the I picture recordingposition becomes a registration point.

The registration trigger from the MPU may be generated, for example,once each time the user inputs a registration instruction or the MPU mayautomatically generate the registration trigger at the time of recordingstart/termination with respect to the optical disk 10 or at the time ofchange of scenes of video or audio. It is preferable that the user canspecify the above selection via the key-in section 49.

Next, the MPU in the microcomputer block 30 detects the physical sectornumber M (head sector address of the I picture) which is now beingrecorded on the optical disk 10 via the disk drive 32 and data processor36 and stores the same in the RAM (step S103), further detects the cellnumber N of a cell which is to be defined (that is, which includes the Ipicture as the index image) and stores the same in the RAM (step S104).

Then, the MPU in the microcomputer block 30 determines whether therecording operation is terminated or not according to the instructionfrom the key-in section 49 or via the disk drive 32 and data processor36 (step S105). If the recording operation is not terminated, theprocess is returned and the step S101 is effected again after the elapseof preset time. If it is detected in the steep S105 that the recordingoperation is terminated, the cell number N stored in the step S104 isregistered in the index scene information 120 of the PGC informationtable 110 shown in FIG. 8 on the optical disk 10 (step S106).

Next, the MPU in the microcomputer block 30 searches the PGC informationtable 110 shown in FIG. 8 and determines the number (PGC information #X)of PGC information containing the cell number N described in the indexscene information 120 (step S107).

Then, the MPU in the microcomputer block 30 records the physical sectornumber M stored in the RAM in the step S103 on the optical disk 10 (stepS108). For example, if the PGC information searched for in the step S107is #1, the physical sector number M is recorded in the column of theindex scene pointer address of the index scene pointer information 134(FIG. 13) of the cell playback information 130 in which the PGCinformation is #1.

Basically, video data which is now being recorded on the optical disk 10is continuous on the time base if the recording thereof is notinterrupted and the continuous portion can be grouped into the same typefrom the viewpoint of the contents thereof. The grouping is effected inthe unit of cell as described before. If the actual recording operationis considered, one cell is generated by the recording start andrecording termination operations. Therefore, as the position informationof the index image, one physical sector number M of the typical Ipicture of a desired cell may be registered.

In the DVD specification, MPEG2 is used for vide encoding. In the MPEG2(also, in the MPEG1), the encoding operation is effected in a cyclecalled GOP as shown in FIG. 18. An intra-coding image screen (I picture)and an inter-coding image screen (P picture, B picture) are contained ineach GOP, but since the former is an image screen in which the coding iseffected only in the image screen thereof and the latter is an imagescreen obtained by predicting the other image screen as a referenceimage screen, the latter cannot be used as an index image. Therefore, inthe pointer recording mode of FIG. 17, the I picture is used as theindex image and the position information thereof is set as theregistration point as shown in FIG. 18.

Next, the index image registration procedure by the index imagerecording mode is explained by use of the flowchart shown in FIG. 19.

Like the case of the pointer recording mode, if the user first suppliesa registration instruction of index image via the key-in section 49, theMPU in the microcomputer block 30 determines that the registrationtrigger is present as shown in the step S201 and issues a registrationtrigger to the encoder section 50. The registration trigger from the MPUmay be generated, for example, once each time the user inputs aregistration instruction or the MPU may automatically generate theregistration trigger at the time of recording start/termination withrespect to the optical disk 10 or at the time of change of scenes ofvideo or audio. It is preferable that the user can specify the aboveselection via the key-in section 49.

Next, if it is determined in the step S201 that the registration triggeris present, the MPU in the microcomputer block 30 detects the physicalsector number M (head sector address of the I picture) which is nowbeing recorded on the optical disk 10 via the disk drive 32 and dataprocessor 36 and stores the same in the RAM (step S202) and starts theindex image creating section 58 to create an I picture to be registeredas the index image (step S203). Then, the index image data thus createdis formed into a packet form together with the present PGC number andstored into the index image buffer memory 59.

Next, the MPU in the microcomputer block 30 determines whether therecording operation is terminated or not according to the instructionfrom the key-in section 49 or via the disk drive 32 and data processor36 (step S205). If the recording operation is not terminated, theprocess is returned to the step S201.

If it is detected in the steep S205 that the recording operation isterminated, a logical address of the picture address table shown in FIG.20 is acquired from the volume & file management area 70 which ispreviously read out on the optical disk 10 (step S206). Then, thecontents of the picture address, more specifically, the PGC number N,the head sector address of the index image actually recorded, the headsector address of the I picture and the like are added and updated (stepS207).

Then, the MPU in the microcomputer block 30 reads out the index imagedata which is created by the index image creation section 58 in the stepS203 and stored into the index image buffer memory 59 in the packet formand forms the readout index image data into a pack form. Then, the MPUrecords the index image data set into the pack form in an area (area inthe picture object 84) on the optical disk 10 which is defined by thecontents of the picture address table in the steps S206, S207 via thedata processor 36 and disk drive 32 (step S208).

Then, whether or not all of the index image data stored in the indeximage buffer memory 59 is read out is determined (S209). If index imagedata is left behind in the index image buffer 59, the PGC number N ofthe next index image is specified and the process of the steps S207,S208 is repeatedly effected. If all of the index image data is read out,an image having the playback control information 102 and volume & filemanagement area 70 recorded therein as shown in FIG. 3 is sequentiallyupdated (steps S211, S212) and the process is terminated.

Next, the format of the user menu file on the optical disk 10 associatedwith the index image is explained. The user menu file is a file name ofthe reduced drawing control information 108 (the reduced drawing controlinformation is hereinafter referred to as a user menu file) shown inFIG. 3. The format of the user menu file can conceptually take aconstruction as shown in 20 and is specifically constructed as shown inFIGS. 21 and 22.

First, as indicated from the top to the bottom in FIG. 20, data in theuser menu file 108 is described in the order of a first anchor pointer,picture address table, index image data group, backup of the pictureaddress table and second anchor pointer.

A pointer address called the first anchor pointer (a, p, b, q) is firstset in the user menu file, and “a” and “p” are a start address and endaddress of the picture address table and “b” and “q” are a start addressand end address of backup data of the picture address table.

Next to the first anchor pointer, the picture address table is recorded.Menu index information (INFO1) is recorded in the first position of thepicture address table. The menu index information contains the number ofindex pictures, the number of information pictures, the number ofdefective areas and the number of wall paper picture registering sheets.Among them, the number of information pictures indicates the number ofregistered sheets of index images recorded in the pointer recording mode(the image is called an information picture). The number of indexpictures is equal to the total sum of the number of index imagesrecorded in the index image recording mode and the number of informationpictures.

The “correlation table between PGC and index image recording position”set after the menu index information is actual data relating to eachindex image constructing the user menu file and the PGC number (PGCN) ofthe index image, PTS (the playback timing of the I picture as the indeximage), the head address (c) of the index image, the number of usesectors of the index image including the dummy area, the size only ofthe index image, the head address (pointer) of the I picture as theindex image, text data used for searching and entitling, the headaddress and data length of a defective area if the defective area ispresent in the file, the number of wall paper picture registering sheetsof the user menu and the head address (s) thereof and the like arerecorded in this portion. The total data amount of the picture addresstable is aligned with 32 kbytes (32k×N bytes) as will be describedlater.

After the picture address table, an actual index image data groupcreated in the index image data creation section 58 shown in FIG. 15 isrecorded. Further, after the correlation table, the backup of thepicture address table is recorded. The backup is recorded for insuranceagainst breakage of the picture address table. The index image data andbackup are formed in a pack form and are actually recorded in thepicture object 84 shown in FIG. 3. The index image and backup are alsoaligned with 32 kbytes as will be described later.

In the last position of the user menu file, a second anchor pointer (a,p, b, q) which is the same as the first anchor in the head position ofthe user menu file is described. The reason for this arrangement is thatthe file is normally destroyed from the head management area to whichaccess is frequently made. By setting the anchor pointer in the lastposition of the file, the safety is further enhanced.

The user menu file of FIG. 20 has the following features.

(1) At least one menu selection index image data (that is, index imagedata) which expresses a still image of at lest part of video data isrecorded in the same user menu file.

(2) All of the index image data items recorded on the optical disk 10(DVD-RAM disk, DVD-RW disk or DVD-R disk) are collectively managed (avideo signal corresponding to the recording position is specified) byuse of the picture address table.

More specifically, information shown in FIGS. 21, 22, for example, iswritten into the user menu file of FIG. 20. That is, as shown in FIGS.21, 22, as the first anchor pointer for the picture address table, thestart position of the picture address table, the end position of thepicture address table, the start position of a spare picture addresstable and the end position of the spare picture address table aredescribed. As the picture address table (corresponding to 108B of FIG.3), menu index information (INFO1), a plurality of index pictureinformation items (INFO2), defective area information (INFO4), wallpaper picture information (INFO5) and padding data are described. As thesecond anchor pointer for the picture address table, the start positionof the picture address table, the end position of the picture addresstable, the start position of the backup of the picture address table andthe end position of the backup of the picture address table aredescribed. In the picture address table shown in FIGS. 21, 22, theinformation picture information INFO3 shown in FIG. 3 may be adequatelydescribed.

Menu index information of FIG. 21 contains the number of index pictures,the number of information pictures, the number of defective areas andthe number of wall paper pictures. Index picture information containsthe contents characteristic, ID of the index picture program chain, thetime code of the index picture, the start position of the index picture,the number of sectors used for recording the index picture, the picturesize, and the address and searching text data of the index picture (Ipicture).

As the time code of the index picture, PTS of the head sector of the Ipicture is described. However, it is possible to describe the number offields and the number of pictures (the number of fields×2) as the timecode. Further, a picture which can be specified as the index picture isnot limited to the I picture, but it is possible to specify the Ppicture or B picture (that is, specify the field number) to derive the Ipicture as will be described in another embodiment.

In the contents characteristic contained in the index pictureinformation, “1” is described if the index image used in the user menuis already recorded and “0” is described if only the recording position(address) of the index image is recorded.

The index picture information in a case where a user menu image isspecified only by use of an address contains the contents characteristicin which “0” is described as shown in FIG. 22, ID of the informationpicture program chain PGC, the time code in the PGC corresponding to theinformation picture, and an address of the PGC corresponding to theinformation picture.

The wall paper picture information of FIG. 22 contains the number ofwall paper pictures which can be used as the wall paper picture of theuser menu (the number of a registered wall paper picture), the startposition of the wall paper picture, and the number of sectors used in anarea in which the wall paper picture is recorded and the padding data ofFIG. 22 contains the contents of the index picture, the contents of thedefective area and the contents of the wall paper picture.

Next, the “32-kbyte aligning process” is explained.

The internal portion of the user menu file shown in FIGS. 20 to 22 isdivided for every 32 kbytes corresponding to a unit of error correctioncode (ECC block) irrespective of the already recorded area andnon-recorded area and the position of the “ECC boundary” which is theboundary portion thereof is previously determined.

When the index image data, anchor pointer, picture address table andbackup of the picture address table are recorded, the recording startposition and the recording end position of all of the data items arerecorded to coincide with the “ECC boundary” positions.

If the data amount is slightly smaller than an integral number of 32kbytes, a “dummy area” is added as shown in FIG. 20 so as to make therecording end position coincident with the “ECC boundary” position. The“dummy area” indicates the “padding” area in FIG. 21.

At the time of recording/erasing of index image data, therecording/erasing operation of information is effected for each “ECCboundary”. In this case, since it is not necessary to change part ofinformation in the ECC block, reduced data can be directly overwrittenin alignment with the ECC boundary at the recording time.

If the “32-kbyte aligning process” described above is effected, theoperation speed of the recording/erasing operation in the unit of ECCblock can be enhanced since it becomes unnecessary to correct errorcorrection information which is added to record/erase the index imagedata in the unit of ECC block.

The user menu file of FIG. 20 is designed by considering thetransportation to another type of recording medium by use of a personalcomputer or the like. Therefore, the storage addresses of the indeximage, wall paper picture and picture address table of the user menu areexpressed by difference addresses (relative addresses) from the headposition of the user menu file.

In the “correlation table between PGC and index image recordingposition” in the picture address table of FIG. 20, two lines from thePGC number to the searching text data size express one set ofcorrespondence tables. In this case, the relation between the recordedindex image data and the video signal can be understood based on thecorrespondence relation between the time code (PTS) of the video signaland the head address. Further, by searching the whole correlation table,the non-recorded area in the user menu file or the free area obtained byerasing index image data can be detected and new index image data can berecorded in the area.

In the user menu file of FIG. 20, a defective area is managed. Aspecific processing method effected in a case where the picture addresstable is damaged by dusts or scratches attached to the surface of thedisk (recording medium) 10 is explained.

First, the damage of the picture address table due to the dust orscratch on the surface of the disk (recording medium) is detected(whether it is damaged or not can be determined according to whether theerror correction of the ECC block fails or not).

When the damage is detected, anchor pointer information is read out, thebackup data address of the picture address table is checked and thebackup data of the picture address table is read out.

Next, the non-recorded area in the user menu file is searched for by useof the correlation table between the index image recording positions ofFIG. 20. Then, index image management data is recorded in thenon-recorded area in the user menu file and the address information ofthe anchor pointer is updated.

Then, the location in which the picture address table is damaged by thedust or scratch on the surface of the disk (recording medium) isregistered as a defective area in the correlation table between theindex image recording positions of FIG. 20.

If the user menu file format of FIGS. 20 to 22 is used, the followingeffect can be expected.

(a) The index image data can be added/searched and the access speed canbe enhanced by effecting the “32-kbyte aligning process”.

(b) When a plurality of index images are simultaneously displayed on thedisplay section of a monitor display (not shown), it becomes necessaryto access a corresponding index image data position on the recordingmedium for each reduced image screen. If index position data items arerandomly arranged (scattered) on the recording medium, it takes a longtime to access and time required for displaying the plurality of indeximages becomes long. However, as shown in FIG. 20, if the plurality ofindex manage data items are collectively arranged in the same user menufile, the plurality of index images can be displayed at high speedsimply by playing back the user menu file.

(c) By collectively managing the whole index image data by use of thepicture address table, the management of the process for deleting oradding the index image data becomes easier. That is, the searchingoperation for the non-recorded area (or the index image data deletingarea) in the user menu file becomes easier and additional registrationof new index image data can be effected at high speed.

(d) In the DVD video recorder shown in FIG. 15, data is collected forevery 16 packs (=32 kbytes) to make an ECC block in the data processor36 and the ECC block is recorded on the optical disk (DVD-RAM, DVD-RW orDVD-R) 10 after error correction information is attached thereto.Therefore, if part of information in the ECC block is changed, it isnecessary to correct the attached error correction information, theprocess becomes troublesome and it takes a long time to effect theinformation changing process. However, by effecting the “32-kbytealigning process”, correction of the error correction informationattached when the index image data is erased in the unit of ECC block ismade unnecessary and the user menu data can be erased at high speed.

(e) The high reliability of the anchor pointer, picture address tableand backup data of the picture address table can be securely attained bythe following method.

Secure attainment of the reliability of the picture address table

A backup area of the picture address table is provided to make ready fora case wherein the picture address table becomes defective and if thedefect occurs, the recording location can be moved.

Secure attainment of the reliability of the anchor pointer informationindicating the recording location of the picture address table

The anchor pointer information is independently constructed in an ECCblock to suppress the data changing times and the same information isrecorded in two locations (first and second anchor pointers in FIG. 20).

Defect management process

In a case where information playback from the picture address table oranchor pointer becomes impossible due to the dust or scratch on thesurface of the optical disk (recording medium), data is read out fromthe backup section and recorded in another recording position again. Asa result, it is prevented that the defective area is registered and thedefective area is erroneously used again.

A closed caption or multiplexed character is superposed on the originalimage in the index image data used for the user menu in some cases. Insuch a case, the index image may be constructed after the character ismultiplexed. Further, it is considered that the index image may beconstructed only by use of character data.

FIG. 23 shows a concrete display example of the menu screen obtained byuse of the index image registered on the optical disk 10 in thisembodiment. In this example, an image of a map of the entire area ofAfrica as an image 1, images of maps of discrete countries as images 2,3 . . . are displayed in the form of a list. The menu screen isdisplayed by depressing a menu key in the key-in section 49. The userselects an image of a desired number in the screen so as to search forthe position on the optical disk 10 on which the selected image isrecorded and edit the same. Further, by displaying the time code fromthe head point together with the images 1, 2, . . . as shown in FIG. 23,a period of time from the playback start time in which the image isdisplayed can be derived from the recorded image.

Next, another embodiment of this invention is explained. In thisembodiment, as shown in FIG. 24, a plurality of cells 94 are collectedto construct groups of programs (PG) 201 and the playback image iscontrolled in the unit of program. The position of the index image isspecified by the cell number in the program and the display time (thenumber of fields) of the index image to be registered.

In this embodiment, as shown in FIG. 25, program playback information202 is inserted between PGC general information 128 and cell playbackinformation 130 in the format shown in FIG. 8. The contents of theprogram playback information 202 include program type information 204,the number 206 of cells contained in the program, text information 208and index image position information 210 and the position of the indeximage is specified by the cell number and the display time thereof (thenumber of fields) as shown in FIG. 26.

FIG. 27 is a flowchart showing the procedure for registering the displaytime on the optical disk. First, the MPU in the microcomputer block 30determines whether or not the registration trigger is present as shownin the step S301. If the registration trigger is present, the MPUdetects and holds the display time of the picture which is now beingrecorded on the optical disk 10, that is, the number F of fields in theprogram (PG) which is now being recorded (step S302). Then, the MPUdetects and holds the cell number which is now to be defined (stepS303).

Whether or not the recording operation is terminated is determined inthe step S304 and if it is not terminated, the step S302 is effectedagain. If it is determined in the step S304 that the recording operationis terminated, the MPU in the microcomputer block 30 registers the cellnumber N and field number F held in the steps S303 and 302 into the cellnumber 212 and index image display time of the program playbackinformation 202 of FIG. 25.

If other pointers (cell number and field number) are further held (step306), the step S305 is effected again and all of the pointers held areregistered into the index image position information 210 of the opticaldisk.

In the former embodiment, the index image is used to specify the headaddress of the I picture, but this embodiment is not limited to thiscase and it is possible to specify the B picture or P picture.

FIG. 28 shows the relation between VOBU and the field in MPEG. An areafrom an I picture to a next I picture is collected as VOBU. The numberof pictures in one second is determined to be 30 in the NTSC system.Since one picture corresponds to two fields, 60 fields are displayed inone second. In this example, an area from an I picture to a next Ipicture is defined as one GOP. However, one VOBU is not limited to oneGOP and may include a plurality of GOPs in some cases.

A time map table 111 as shown in FIG. 29 is recorded in the playbackcontrol information 102 of FIG. 6 to indicate the relation between thedisplay time of each picture and the recording address on the opticaldisk for each VOBU. If the playback time (field) of each picture isspecified, the position address on the optical disk on which it isrecorded can be calculated.

FIG. 30 is a flowchart showing the calculation procedure. First, the MPUin the microcomputer block 30 reads out the specified field number fromthe index image display time of the program playback information 202 ofFIG. 25 (step S401). Then, the number of the field is sequentially addedstarting from the first VOBU of the time map table 111 of FIG. 29 toderive the VOBU number which contains the specified field number (stepS402).

Next, the head address of VOBU which contains the specified field numberis calculated from the time map table 111. As shown in FIG. 28, sincedata of the I picture is recorded in the head address of VOBU, the MPUin the microcomputer block 30 accesses the head address of VOBU anddisplays the I picture as the index image (step S404).

In the above embodiments, registration of the index image is explained,but this invention can also be similarly applied to a case whereinspecified audio data is registered.

Further, this invention is not limited to the recording/playbackapparatus, but can be applied to a playback apparatus, that is,playback-only apparatus having no recording function.

As described above, according to this invention, the user can instantlydetect the recording information on the recording medium by recordingposition information (pointer) indicating the recording position of animage selected from the main record data on the recording medium orrecording an image selected from the main record data as the indeximage, and utilizing information of an image and voice recorded in therecording position indicated by the position information or the indeximage as a menu at the time of playback. Therefore, the user can rapidlysearch for a desired position based on the menu and efficiently effectthe editing operation such as the operation for erasing and replacinginformation in a desired area on the recording medium.

1. An information recording method for recording information on aninformation recording medium, where the information recording mediumincludes an object recording area for recording an object which includesa plurality of object units each including video data and audio data,and a control information recording area for recording controlinformation, wherein: the control information recording area includes afirst area for allowing a plurality of program chain informationrespectively associated with the plurality of object units to berecorded in the first area, and the object units are allowed to includea plurality of specific images, and are included into optional cells;the first area includes a second area for allowing a plurality of cellinformation respectively associated with the plurality of program chaininformation to be recorded in the second area, and the plurality of cellinformation includes optional entry points of the plurality of cells;the control information recording area further includes a third area forallowing information of a time map table to be recorded in the thirdarea, the third area being provided for storing a plurality ofinformation related to a playback time of each of the specific imageswhen the specific images are included in the object units; and theinformation of the time map table is included in the controlinformation, the information recording method comprising the steps of:recording the object including the object units; and recording thecontrol information including the information of the time map table. 2.An information reproducing method for reproducing information from aninformation recording medium, wherein the information recording mediumincludes an object recording area recording the object which has aplurality of object units each including video data and audio data, anda control information recording area which records control information,wherein: the control information recording area includes a first areafor allowing a plurality of program chain information respectivelyassociated with the plurality of object units to be recorded in thefirst area, and the object units are allowed to include a plurality ofspecific images, and are included in optional cells; the first areaincludes a second area for allowing a plurality of cell informationrespectively associated with the plurality of program chain informationto be recorded in the second area, and the plurality of cell informationinclude optional entry points of the plurality of cells; the controlinformation recording area further includes a third area for allowing aninformation of a time map table to be recorded in the third area, thetime map table being provided for storing a plurality of informationrelated to a playback time of each of the specific images when thespecific images are included in the object units; and the information ofthe time map table is included in the control information, theinformation reproducing method comprising the steps of: reproducing thecontrol information including the information of the time map table; andreproducing the specific images included in the object units based on atleast the information of time map table.
 3. An information reproducingapparatus for reproducing information from an information recordingmedium, wherein the information recording medium includes an objectrecording area recording the object which has a plurality of objectunits each including video data and audio data, and a controlinformation recording area which records control information, wherein:the control information recording area includes a first area forallowing a plurality of program chain information respectivelyassociated with the plurality of object units to be recorded, the objectunits are allowed to include a plurality of specific images, and areincluded into optional cells; the first area includes a second area forallowing a plurality of cell information respectively associated withthe plurality of program chain information to be recorded in the secondarea, and the plurality of cell information includes optional entrypoints of the plurality of cells; the control information recording areafurther includes a third area for allowing information of a time maptable to be recorded in the third area, the time map table beingprovided for storing a plurality of information related to a playbacktime of each of the specific images when the specific images areincluded in the object units; and scene points are provided for theobject unit, and the control information includes at least a pluralityof information of the scene points for the object units, the informationreproducing apparatus comprising: a reproduction unit configured toreproduce the control information including at least the plurality ofinformation of the scene points of the object units; and to reproducethe specific images of the object units based on the plurality ofinformation of the scene points.